Many bulky spun yarns have conventionally been obtained by a process wherein two or more staple fibers having different thermal shrinkages are mixed and subjected to a heat treatment after a yarn is formed. According to this method, since the staple fibers having a high thermal shrinkage have a tendency to concentrate at the central portion of the spun yarn, the spun yarn thus obtained has a disadvantage in that it lacks softness, more specifically the conventional spun yarn lacks handle of bulkiness and is not provided with rich and well formed feeling. If fine fibers are used to eliminate the above-mentioned disadvantage, there results another disadvantage in that the textile obtained from the spun yarn lacks stiffness or springiness. In other words, the thus obtained textile lacks liveliness. In addition, as a result of the concentration in the spun yarn of fibers having high thermal shrinkage the fibers having low thermal shrinkage move toward the outside of the spun yarn, and during the movement of the fibers the alignment of the fibers having low thermal shrinkage is randomly disturbed. Accordingly, this produces disadvantage in that the hand of the obtained spun yarn is rough and harsh.